1. Field of the Invention
The invention relates to a torsion damping device between an axially oriented coaxial drive shaft and driven shaft in an automotive temporary coupling system, comprising elastic members, and to a hydrodynamic converter equipped with such a damping device.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
The invention relates more particularly to a torsion damping device between an axially oriented coaxial drive shaft and driven shaft in an automotive temporary coupling system, the device having:                a torque input element and a torque output element;        at least one first, upstream circumferentially acting elastic member, an upstream circumferential end face of which is capable of being loaded by or of loading the input element;        at least one second, downstream circumferentially acting elastic member, a downstream circumferential end face of which is capable of loading or of being loaded by the output element;        at least one first radial phase washer, the downstream end face of each upstream elastic member being capable of loading or of being loaded by an upstream radial phasing face of the phase washer, and the upstream end face of each downstream elastic member being capable of being loaded by or of loading a downstream radial phasing face of the phase washer, such that the two elastic members are mounted in series.        
Damping devices of this kind are installed, for example, in clutch arrangements such as hydrodynamic converters. A converter of this kind has, for example, a rotating housing that is capable of transmitting drive torque to the damping device by means of a friction locking clutch, sometimes called a “lock-up” clutch. The converter also has a turbine wheel mounted rotatably inside the housing.
A combustion engine exhibits irregularities due to the succession of combustion events in the engine cylinders. Torsion damping means allow these irregularities to be filtered before the drive torque is transmitted to a transmission. This is because the vibrations must be damped before they enter the transmission and produce unacceptably troublesome noise.
To accomplish this, it is known to interpose a torsion damping device between the drive shaft and the transmission shaft. The torsion damping device is generally arranged in a clutch system that allow temporary rotational connection of the drive shaft to the transmission shaft.
The torsion damping device generally has circumferentially acting elastic members that are interposed between a torque input element and a torque output element.
In so-called “long travel” damping devices, the elastic members are mounted, in groups of at least two elastic members, in series between the input element and output element.
In such a configuration, a phasing tab is interposed between the two elastic members of said group. This ensures that the elastic members work substantially in circumferential compression. The phasing tabs are, for example, carried by phase washers.
The adjacent elastic members of two successive groups are received in washer receptacles or windows that have a guidance function. Each window is delimited circumferentially by an abutment tab.
The receptacles are formed into washers that have a guidance function. These washers are constituted, for example, by the phase washers; in this case the abutment tabs that circumferentially delimit each window are phasing tabs.
The damping device is sometimes configured in such a way that the phase washer is rotationally connected to the converter turbine wheel.
In this case, when drive torque is inputted through the converter turbine wheel, certain elastic members (the upstream members) are not loaded. These elastic members are capable of sliding circumferentially in their window, thus causing parasitic noise to appear.